It is known in the art that a solar panel's operating point (voltage and current) may be decided by an electronic circuit called a maximum power point tracker (“MPPT”) to keep the power level of an output of the solar panel to reach a maximum. This operating point of the solar panel is called maximum power point (“MPP”). Currently, a solar panel having MPPT would adjust the solar panel to operate at MPP to charge a battery. However, operating the panel at MPP does not guarantee maximum current flow into the battery connected when charging the battery (e.g., during a “bulk charging” mode), which in turn minimizes the time needed for charging a battery to full capacity.
More specifically, different types of batteries come with different impedance characteristics that may affect the current flow from a solar panel into a connected battery. Each type of battery also has its unique minimum charge voltage, maximum charge voltage, minimum charge current, and maximum charge current. Similarly, the charging status of a battery can affect the voltage level required for charging the battery. Moreover, as ambient temperature changes and/or sunlight condition varies, MPP can drift so that the solar panel produces an output at a different power level. Therefore, it is desirable to employ a control system that monitors and adjusts the current and voltage level of the solar panel's output to maximize the current flow from the solar panel into the battery connected in response to different variables including, for example, different types of battery, the charging status of the battery, temperature of the panel, or sunlight condition (often measured in irradiance).
Further, in conventional approaches, when the voltage level on the solar panels drops to a level that it is unable to provide sufficient minimum charge voltage as required to charge the battery, the energy generated by the panel is lost. Therefore, it is also desirable to provide a mechanism in the solar panel system to enable a boost to the voltage level of the panel's output so that the battery can be charged even in low light conditions. This enables an extension of the energy harvesting period of the solar panel when the panel is experiencing low light conditions such as dusk, dawn or clouds.